1. Field of the Invention
The present invention relates to an induction heating apparatus capable of displaying temperature on an insulating plate thereby eliminating danger of a burn.
2. Related Art
FIG. 3 is a cross-sectional view of an induction heating apparatus for displaying temperature on an insulating plate as shown in, for instance, Japanese Examined Utility Model Publication No. 37083/1984. In FIG. 3, an induction coil table 2 is placed inside an outer casing 1 and an induction coil 3 is arranged on the induction table 2. An insulating plate 5 is attached to the outer casing 1 above the induction coil 3.
The insulating plate 5 is adapted to receive a cooking pot 4 on the upper surface on which a pattern diagram 6 is drawn so that the cooking pot 4 is put on the diagram 6. A paint of a color which is changeable depending on temperature is coated on the upper surface of the insulating plate 5 or the pattern diagram 6.
In the induction heating apparatus constructed as abovementioned, when the cooking pot 4 is on the insulating plate 5 for cooking, or the cooking pot 4 is removed from the insulating plate 5 after completion of the cooking, the insulating plate 5 is at a high temperature by heat transfer from the cooking pot 4.
Since the upper surface 5a of or the pattern diagram 6 on the insulating plate 5 is coated with the paint of a color which is changeable depending on temperature, the color is kept unchanged until the temperature of the insulating plate 5 becomes a predetermined value or less, whereby a user is aware of it and a burns caused by carelessly touching the insulating plate is prevented.
In the conventional induction heating apparatus, there are disadvantages as follows. The paint coated on the upper surface 5a of the insulating plate or the pattern diagram 6 may be peeled off when friction occurs between the upper surface 5a or the pattern diagram 6 and the cooking pot 4 or when the insulating plate 5 is polished by a polishing powder. Temperature indicating function is decreased due to deterioration in color-changing properties of the paint when the insulating plate is heated to a high temperature.